A US woman who shot and killed her husband and two adult children before taking her own life is thought to have committed the shocking crime as a result of being ostracised from the religion she was raised in.

A federal judge sentenced a former Arkansas judge Wednesday to five years in prison — a stiffer punishment than prosecutors recommended — after he admitted giving young male defendants lighter sentences in return for personal benefits that included sexual favours.

Every time I tell a mate I’m doing a story on cryptocurrency, they invariably ask me the same two questions: should they invest their own hard-earned money, and which cryptocurrency will get them a Lamborghini/yacht/island quickest?

In a 60 Minutes online exclusive, reporter Liz Hayes quizzed Australian Prime Minister Malcolm Turnbull on his relationship with the unpredictable Twitter aficionado and US president Donald Trump ahead of their meeting at the White House Friday.

Malaria breath test breakthrough

Diagnosing the deadly malaria disease could soon be as simple as taking a breath test.

Australian scientists have made the groundbreaking discovery that malaria-infected patients have higher levels of certain chemicals in their breath.

The foul-smelling chemicals are undetectable to the human nose, but can be used to detect the disease much earlier than the traditional method of using a microscope to find parasites in blood.

The level of the chemicals increase with the severity of the mosquito-borne infection and disappear after cure.

"What is exciting is that the increase in these chemicals were present at very early stages of infection, when many other methods would have been unable to detect the parasite in the body of people infected with malaria," Dr Stephen Trowell, Research Group Leader at CSIRO said.

He was confident the breakthrough can be used to develop a cheap, quick and effective method of testing for the mosquito-borne disease in areas where it is endemic.

"We are also working with colleagues to develop very specific, sensitive and cheap 'biosensors' that could be used in the clinic and the field to test breath for malaria," he said.

In 2013 there were almost 200 million cases and over half a million deaths due to malaria, the World Health Organisation reports.